A court has blocked the export of 25 captive dolphins trained in the Philippines to become show animals at a Singapore casino, a Filipino official and animal rights groups said Saturday.

A civil suit filed by the rights groups alleged the traffic in live Indo-Pacific bottlenose dolphins for sport or entertainment was illegal, cruel and would cause the extinction of the species.

The large marine mammals were shipped to a marine park in the northern Philippines between 2008 and 2011, said Anna Cabrera, head of the Philippine Animal Welfare Society.

"The dolphins, caught in the wild from the Solomon Islands, were forcibly snatched from their families and will live short, miserable lives in captivity as show animals for Resorts World in Singapore," Cabrera said in a statement.

The Bureau of Fisheries and Aquatic Resources, the government office in charge of the dolphin permits, would formally respond to the court order on Monday, said bureau director Asis Perez.

He disputed the suit's allegation that dolphin trading would be detrimental to the survival of the species and thus not authorised by the Philippines' wildlife conservation law.

"These are regulated species that you can trade, and we are supposed to regulate the trade," he told AFP.

"They were sent here only for the purpose of training them," he said.

The importers had complied with all regulatory requirements, and have asked for government permission to ship them to Singapore after their training, Perez added.

The dolphins were to have been sent to Resorts World Sentosa, a giant casino resort in Singapore, according to a copy of the written order issued by regional trial court judge Bernelito Fernandez.

Fernandez said he was studying the animal rights groups' plea to ban dolphin traffic in the Philippines, said the court document, furnished to AFP by Earth Island Institute, one of the other plaintiffs.

Court officials were unavailable for comment Saturday.

Resorts World Sentosa's Philippine lawyers named in the suit could not be contacted.

Swiss-based conservation group International Union for the Conservation of Nature said on its website that there were many threats on local bottlenose dolphin populations.

However, "the species is widespread and abundant, and none of these threats is believed to be resulting in a major global population decline", it added.